近接地铁隧道基坑开挖静动力学行为研究

Research on static and dynamic performance of the foundation pit excavation adjacent to subway tunnels

基坑开挖对近接地铁隧道造成不利影响,甚至危及隧道结构和运营安全。此外,隧道的存在也对基坑力学特征产生明显影响,从而改变基坑周边地层和支护结构的受力变形行为。为此,结合某广场基坑工程实践,采用三维数值模拟手段,分析近接隧道基坑开挖施工力学特征,重点探讨基坑开挖对盾构隧道结构变形的影响,以及基坑开挖过程中,地铁列车振动对基坑施工力学行为的影响,揭示基坑与隧道之间的静动力学相互作用机理,为以后类似地铁隧道保护提供理论指导和现实参考。

Foundation pit excavation would have adverse effects on adjacent subway tunnels, and even endanger the safety of tunnel structures and operation. In addition, the existence of the tunnel wound have significant effects on the mechanical characteristics of foundation pit, thereby altering force and deformation behavior of the strata around foundation pit and supporting structures. In this paper, combined with a square pit engineering in practice, three - dimensional numerical simulation method was adopted to analyze the mechanical features of adjacent tunnel pit excavation construction. Meanwhile, the effect of foundation pit excavation on the deformation of shield tunnel structures and the effect of metro trains vibration on mechanical behavior of foundation pit construction were mainly discussed. In this way, the mechanism of static and dynamic interaction between the foundation pit and the tunnel was revealed, which could provide theoretical guidance and practical reference for the similar subway tunnel protection in the future.